温度对微波溶剂热合成LiMnPO_4/C结构及性能的影响  

Effects of temperature on the structure and performance of LiMnPO_4/C prepared by a microwave solvothermal method

作　　者：刘真珍[1] 黄巧英[1] 姚华[1] 苏静[1,2] 龙云飞[1,2] 吕小艳[3,2] 文衍宣[1,2] 

机构地区：[1]广西大学化学化工学院,南宁530004 [2]广西高校新能源材料及相关技术重点实验室,南宁530004 [3]广西大学新农村发展研究院,南宁530004

出　　处：《功能材料》2016年第5期159-164,共6页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(21366006)

摘　　要：以MnSO_4·H_2O和Li_3PO_4前驱体为原料,以水和二甘醇(DEG)的混合物为溶剂,采用微波溶剂热法合成LiMnPO_4/C复合正极材料,用XRD、SEM、CV、EIS和恒电流充放电技术研究了温度对微波溶剂热合成材料的结构、微观形貌和电化学性能的影响。结果表明,随着反应温度的增加,块状前驱体Li_3PO_4逐渐转变为片状LiMnPO_4。190℃时合成的材料为Pmnb空间群橄榄石型结构LiMnPO_4晶体。该温度得到的LiMnPO_4/C的1C放电比容量为108.3mAh/g,循环50次后容量保持率高达99.9%。LiMnPO4/C composites were prepared by a microwave solvothermal method using MnSO4 H2O andLi3PO4 precursor as source materials, water and diethylene glycol mixed solvents as reaction solvents. Theeffects of temperature on the structure and electrochemical performances of samples were investigated by XRD,SEM, CV, EIS charge/discharge tests. As the temperature increased, block like Li3 PO4 precursor graduallytransformed into a flaky LiMnPO4. The sample prepared at 190 ℃ formed the olivine structure with the spacegroup Pmnb. The prepared LiMnPO4/C delivered an initial discharge capacity of 108.3 mAh/g with a capacityretention of 99.9% after 50 cycles at 1 C.

关 键 词：锂离子电池 正极材料 磷酸锰锂 微波溶剂热 

分 类 号：TM912.9[电气工程—电力电子与电力传动]